Key to the whole game is timing. “You don’t want to heat yourself up right before bed,” Dr. Augelli told TIME Health. “Cooling down is a signal that tells us we’re supposed to go to sleep.”The optimal timing? Ninety minutes before you want to hit the hay. By then, your body can regulate its circadian rhythms—essentially the signals that tell it when to feel alert and when to feel sleepy. Right after the shower, you’ll heat up and feel more alert and active and possibly creative, but as time passes and you begin the cool-down process, your system will feel more primed for rest instead of still feeling warmer and antsier. Plus, you’ll be dry after 90 minutes—no damp pillow